This weekend, I got a little bit of spare time, and went outside to enjoy some of the nice weather and work on my truck a little. In addition to the standard checking of the fluid levels, throwing away all the trash, etc. I decided to take a little time and redo some of the work I’ve put into the electrical system in the past, and if you know me, you know that it’s probably fairly extensive.
Well, it was. There are a lot of little things, but there are a few primary things I did. I rerouted the antenna feed line for the CB radio through the firewall, so that it wasn’t wrapped around the sharp angled door jamb.
I re-ran the power for my relay system so that it would automatically shut off after the ignition gets turned off. This lets me make sure not to drain my battery in case I leave the amp or my power inverter on.
Last but not least, I fixed my amp. It “broke” a little while back, and I’m not sure exactly why, but when it broke, it sounded a lot like a recurring problem I’ve had with the gain adjustment potentiometer. It was an old electrically noisy pot and when you’d turn it, the amp would go berserk and make not happy noises come out of the speakers. So I took the amp apart and went over the circuit board and re-soldered some of the connections. There were several connections that looked pretty bad, so these could also have been at fault. Anyway, I measured what the resistance of the pot should be at approximately half gain, which is where I kept it most the time anyway, and then replaced the pot with appropriately rated resistors. It seems to work now, so hopefully I’ve fixed whatever is wrong with it, and I won’t accidentally hit the gain knob and make it make very loud unhappy noises.
In other news, I chatted with a buddy of mine yesterday who’s come across some interesting plans on the internet for an interesting very basic, and very low cost HAM radio receiver. He’s gotten the idea to replace the frequency crystal in the design, with a frequency generator IC, and control that with an Arduino microprocessor. That would allow a digital readout of the frequency you are listening for, and allow it to be adjustable (in his version) from about .2 MHz to about 50 MHz. I’m interested in seeing how well this works out for him. There are a lot of interesting things down in those frequency ranges. If it works well I may have to build one. Generally I play in the 144 – 430 MHz ranges, so it would be interesting to see if I can find a frequency generator IC that would work accurately at those frequencies.